The present invention relates to an antenna apparatus, and an electronic toll collection system and an electronic toll collection method using the antenna apparatus. More specifically, the present invention relates to an antenna apparatus capable of ensuring communication with on-vehicle equipment for electronic toll collection and of improving traffic jams to be smoothed, and to an electronic toll collection system and an electronic toll collection method using it.
As shown in FIG. 1, in the above-mentioned antenna apparatus and the electronic toll collection (hereinafter, abbreviated to an ETC) system using it, hitherto, an antenna apparatus 102 is provided in a space over a lane 3 through which an automobile 1 having an ETC on-vehicle equipment 10 passes. An antenna of the antenna apparatus 102 radiates a radio wave having a radio beam emitted area 21 to communicate with the ETC on-vehicle equipment 10 and, thereby, toll collection is electronically performed for the passing automobile 1.
Generally, the antenna apparatus 102 is disposed over a center line of the lane 3, and the ETC on-vehicle equipment 10 is placed in the center of a dashboard inside a front glass of the automobile 1. Thereby, the radio wave is accurately transmitted/received between the antenna apparatus 102 and the ETC on-vehicle equipment 10.
In order to reduce a communication error due to various radio interference noises, a radio beam pattern of the antenna is improved and a reflected wave is suppressed by laying a radio absorbing material, etc.
However, usually, the above-mentioned conventional antenna apparatus and the ETC system using it aim the radio beam emitted area of the antenna apparatus in the center line of the lane. Therefore, if the position of the ETC on-vehicle equipment mounted on the automobile is near a passenger seat and the automobile entering the lane is near the passenger seat side of the lane, there is a great possibility that communication for the ETC on-vehicle equipment is not accurately ensured. If it is incommunicable, the automobile is constrained to stop before an exit or to further reduce the speed and there is a problem in that the automobile cannot smoothly pass through the lane.
In order to solve the aforementioned problems, it is an object of the present invention to provide an antenna apparatus which is controllable so that the ETC on-vehicle equipment mounted on the automobile is in the center of the radio beam emitted area of the antenna apparatus, and also to provide an electronic toll collection (ETC) system using it.
According to the present invention, an antenna apparatus comprises an antenna through which a radio beam is emitted to have a predetermined-directionality, and a light emitting unit having a light emitted area of visible light within the center in the radio beam emitted area of the antenna. In this constitution, a driver of the automobile sensing the emission of the visible light regardless of day and night can pass the ETC on-vehicle equipment through the center of the emitted area of the visible light.
Also, when the visible light emitted from a light source in the light emitting unit in the antenna apparatus is emitted to a wall opposed to the antenna apart therefrom by a predetermined distance, the visible light is substantially circular-shaped, laterally-long-shaped, or vertically-long-shaped in the emitted area.
With respect to the arrangement of the antenna and the light emitting unit in the antenna apparatus, the antenna is in the center and the light emitting unit is around the antenna, for example, at least on one of upper, lower, right, and left sides and four corners. When the light emitting unit is placed on the upper side, lower side, right side, and left side, or on the four corners, the emitted shape of the visible light can be substantially rectangular in the emitted area.
The antenna apparatus may have a horn-type antenna and a sub-reflector which is held by a supporter in a parabola reflection mirror, and a light source of the light emitting unit may be substantially in the center of the sub-reflector.
According to one aspect of the present invention, the ETC system using any one of the above-mentioned antenna apparatus is characterized as follows in the antenna apparatus and the light source of the light emitting unit. The antenna apparatus is held to an arm of a column over a lane through which an automobile passes. And, when the radio beam emitted area of the antenna which the antenna apparatus has is directed to on-vehicle equipment for ETC which is mounted on the automobile, the light source of the light emitting unit emits the visible light to the center in the radio beam emitted area. Further, preferably, the ETC system has a sensor for detecting the entering direction of the automobile which enters the lane in front of the antenna, for driving the light emitting unit when the entrance of the automobile is detected, and for emitting the visible light from the light source of the light emitting unit.
According to another aspect of the present invention, the ETC system using any one of the aforementioned antenna apparatuses is characterized in that the system is provided for a crossing gate. The crossing gate is held to a column to cross the lane through which the automobile passes at the position to prevent the passage of the automobile. And, when the radio beam emitted area of the antenna which the antenna apparatus is directed to the on-vehicle for the ETC which is mounted on the automobile, the light source of the light emitting unit emits the visible light to the center of the radio beam emitted area. In this case, preferably, the ETC system further has a sensor for detecting that the automobile enters the lane, for driving the light emitting unit when the entrance of the automobile is detected, and for emitting the visible light from the light source of the light emitting unit. The light beam is emitted in the center in the radio beam emitted area of the antenna. Therefore, it is advantageous, in particular, when the lane or antenna apparatus cannot be accurately confirmed because the periphery is dark. Incidentally, the emission of the visible light can be economically and effectively provided, by using the sensor cutting off from the control of the ETC system.
The antenna apparatus other than the aforementioned ones is characterized in that the apparatus is a handy-type apparatus being connected to one end of an arm portion having therein a coaxial cable and a power source cable and used by an attendant for ETC. When the emitted area of light emitted from the light emitting unit is directed to the on-vehicle equipment being mounted on the automobile entering the lane for collecting a toll by the attendant, the toll collection is realized by the ETC system using the radio beam emitted through the antenna.